gymnospore

from The Century Dictionary.

• noun A naked spore; a spore without a protecting investment: opposed to chlamydospore.
• noun Specifically, in botany, a spore that is naked in the sense of not being produced in a sporangium.
• noun In the classification of Le Maout and Decaisne, a cellular cryptogamic plant in which the spores, by absorption of the mother-cell, become free in a common cavity. Their group Gymnospores is coextensive with the Bryophyta. No longer used.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A type of spore that does not have a protective envelope, especially one not produced in a sporangium